Phase II study of temozolomide plus thalidomide for the treatment of metastatic melanoma

VEGF/VEGFR axis and its signaling in melanoma: Current knowledge toward therapeutic targeting agents and future perspectives

Melanoma is responsible for most skin cancer-associated deaths globally. The progression of melanoma is influenced by a number of pathogenic processes. Understanding the VEGF/VEGFR axis, which includes VEGF-A, PlGF, VEGF-B, VEGF-C, and VEGF-D and their receptors, VEGFR-1, VEGFR-2, and VEGFR-3, is of great importance in melanoma due to its crucial role in angiogenesis. This axis generates multifactorial and complex cellular signaling, engaging the MAPK/ERK, PI3K/AKT, PKC, PLC-γ, and FAK signaling pathways. Melanoma cell growth and proliferation, migration and metastasis, survival, and acquired resistance to therapy are influenced by this axis. The VEGF/VEGFR axis was extensively examined for their potential as diagnostic/prognostic biomarkers in melanoma patients and results showed that VEGF overexpression can be associated with unfavorable prognosis, higher level of tumor invasion and poor response to therapy. MicroRNAs linking to the VEGF/VEGFR axis were identified and, in this review, divided into two categories according to their functions, some of them promote melanoma angiogenesis (promotive group) and some restrict melanoma angiogenesis (protective group). In addition, the approach of treating melanoma by targeting the VEGF/VEGFR axis has garnered significant interest among researchers. These agents can be divided into two main groups: anti-VEGF and VEGFR inhibitors. These therapeutic options may be a prominent step along with the modern targeting and immune therapies for better coverage of pathological processes leading to melanoma progression and therapy resistance.

Overall and Progression-Free Survival in Metastatic Melanoma: Analysis of a Single-Institution Database

Background

Many new agents are currently in trial in melanoma. It remains unclear, however, what the benefit of a given therapy may be since information on progression-free and overall survival of untreated patients is limited. Since few trials in melanoma have had a non-treated cohort, it remains unclear what survival can be expected in patients who are not treated with chemotherapy.

Methods

To help develop parameters for future trials, we analyzed treatment history and survival in 212 patients with metastatic melanoma seen at our institution between January 1998 and September 2003. A retrospective analysis was done using a database created for melanoma patients at our center. Patient survival information was determined from this database, tumor registry, Social Security index, and direct patient calls. Patient staging information was determined according to the 2001 guidelines. Non–chemotherapy-treated patients with M1c disease were used as “controls.”

Results

The median survival of stage M1c melanoma was 6.0 months. Survival was longer for stage M1a and M1b and shorter in older patients. No significant differences were found in survival based on gender. Among chemotherapy-treated patients, those with progressive disease on treatment or with increased lactate dehydrogenase (LDH) fared worse than those with a clinical response or normal LDH, respectively. Patients treated with either biochemotherapy or temozolomide and thalidomide survived longer than those who received no chemotherapy treatment. Dacarbazine (DTIC) treatment did not prolong survival.

Conclusions

In this retrospective review of patients treated at a single institution, those treated with multiagent chemotherapy but not with single-agent DTIC appeared to have had a survival benefit.

Novel modeling of cancer cell signaling pathways enables systematic drug repositioning for distinct breast cancer metastases

A new type of signaling network element, called cancer signaling bridges (CSB), has been shown to have the potential for systematic and fast-tracked drug repositioning. On the basis of CSBs, we developed a computational model to derive specific downstream signaling pathways that reveal previously unknown target-disease connections and new mechanisms for specific cancer subtypes. The model enables us to reposition drugs based on available patient gene expression data. We applied this model to repurpose known or shelved drugs for brain, lung, and bone metastases of breast cancer with the hypothesis that cancer subtypes have their own specific signaling mechanisms. To test the hypothesis, we addressed specific CSBs for each metastasis that satisfy (i) CSB proteins are activated by the maximal number of enriched signaling pathways specific to a given metastasis, and (ii) CSB proteins are involved in the most differential expressed coding genes specific to each breast cancer metastasis. The identified signaling networks for the three types of breast cancer metastases contain 31, 15, and 18 proteins and are used to reposition 15, 9, and 2 drug candidates for the brain, lung, and bone metastases. We conducted both in vitro and in vivo preclinical experiments as well as analysis on patient tumor specimens to evaluate the targets and repositioned drugs. Of special note, we found that the Food and Drug Administration-approved drugs, sunitinib and dasatinib, prohibit brain metastases derived from breast cancer, addressing one particularly challenging aspect of this disease.

Oncolytic adenovirus with temozolomide induces autophagy and antitumor immune responses in cancer patients

Oncolytic adenoviruses and certain chemotherapeutics can induce autophagy and immunogenic cancer cell death. We hypothesized that the combination of oncolytic adenovirus with low-dose temozolomide (TMZ) is safe, effective, and capable of inducing antitumor immune responses. Metronomic low-dose cyclophosphamide (CP) was added to selectively reduce regulatory T-cells. Preclinically, combination therapy inhibited tumor growth, increased autophagy, and triggered immunogenic cell death as indicated by elevated calreticulin, adenosine triphosphate (ATP) release, and nuclear protein high-mobility group box-1 (HMGB1) secretion. A total of 41 combination treatments given to 17 chemotherapy-refractory cancer patients were well tolerated. We observed anti- and proinflammatory cytokine release, evidence of virus replication, and induction of neutralizing antibodies. Tumor cells showed increased autophagy post-treatment. Release of HMGB1 into serum--a possible indicator of immune response--increased in 60% of treatments, and seemed to correlate with tumor-specific T-cell responses, observed in 10/15 cases overall (P = 0.0833). Evidence of antitumor efficacy was seen in 67% of evaluable treatments with a trend for increased survival over matched controls treated with virus only. In summary, the combination of oncolytic adenovirus with low-dose TMZ and metronomic CP increased tumor cell autophagy, elicited antitumor immune responses, and showed promising safety and efficacy.

Metronomic chemotherapy for cancer treatment: a decade of clinical studies

PURPOSE

Over the past few years, more and more new selective molecules directed against specific cellular targets have become available for cancer therapy, leading to impressive improvements. In this evolving scenario, a new way of delivering older cytotoxic drugs has also been developing. Many studies demonstrated that several cytotoxic drugs have antiangiogenic properties if administered frequently and at lower doses compared with standard schedules containing maximal tolerated doses (MTD). Such a new strategy, named metronomic chemotherapy, focuses on a different target: the slowly proliferating tumour endothelial cells. About 10 years ago, metronomic chemotherapy was firstly enunciated and hereafter many clinical experiences were published related to almost any cancer disease. This review analyses available studies dealing with metronomic chemotherapy and its combination with several targeted agents in solid tumours.

METHODS

A computerized literature search of MEDLINE was performed using the following search terms: metronomic OR "continuous low dose" AND chemotherapy AND cancer OR solid tumours.

RESULTS

Satisfactory results have been achieved in diverse tumour types, such as breast and prostate cancer or paediatric sarcomas. Moreover, many studies have reported that metronomic chemotherapy determined minimal toxicity compared to MTD chemotherapy. Overall, published series on metronomic schedules are very heterogeneous often reporting on retrospective data, while only very few studies were randomized trials. These limitations still prevent to draw definitive conclusions in diverse tumour types.

CONCLUSIONS

Large well-designed studies are eagerly awaited for confirming the promises of metronomic schedules and their combinations with targeted molecules.

Melanoma: from darkness to promise

Metastatic melanoma is one of the most resistant tumors to standard chemotherapy approaches. The median overall survival of patients diagnosed with metastatic melanoma is lower than 9 months. Current approved treatments offer only marginal survival advantages. New immunotherapeutic targets have appeared recently trying to modulate the host immune response against the tumor. New targeted agents have changed the standard of care of other solid tumor types like breast cancer. Here, we discuss the new advances and achievements in the treatment of this highly resistant disease.

Combining temozolomide with other antitumor drugs and target-based agents in the treatment of brain metastases: an unending quest or chasing a chimera?

INTRODUCTION

Medical treatment of brain metastases (BM) is still a controversial issue in cancer therapy being mainly limited by the existence of the BBB. Temozolomide (TMZ) can cross BBB and several clinical trials have been performed attempting to demonstrate the activity of TMZ in combination with whole brain radiotherapy (WBRT) in the treatment of BM.

AREAS COVERED

This review summarizes TMZ-WBRT combination trials highlighting the confounding factors that limit the interpretation of the achieved results and describes the main clinical trials using TMZ in combination with other cytotoxic or biological agents. The main limitations of these trials are: i) patient selection for heterogenous primitive neoplasms and for heterogeneous neuro-functional score; ii) poor penetration across BBB of the other drugs; iii) cumulative toxicity and iv) poor control of extracranial tumor sites.

EXPERT OPINION

Biotechnological, biological and biochemical advances in the management of BM could allow in short time the definition of new schedules based on the rational use of new anticancer weapons. The latter could be cytotoxic agents encapsulated in nanotechnological tools able to cross BBB, lipophilic small kinase inhibitors (lapatinib, sunitinib), mTOR inhibitors and PARP inhibitors combined with old drugs such as TMZ.

First-line temozolomide combined with bevacizumab in metastatic melanoma: a multicentre phase II trial (SAKK 50/07)

BACKGROUND

Oral temozolomide has shown similar efficacy to dacarbazine in phase III trials with median progression-free survival (PFS) of 2.1 months. Bevacizumab has an inhibitory effect on the proliferation of melanoma and sprouting endothelial cells. We evaluated the addition of bevacizumab to temozolomide to improve efficacy in stage IV melanoma.

PATIENTS AND METHODS

Previously untreated metastatic melanoma patients with Eastern Cooperative Oncology Group performance status of two or more were treated with temozolomide 150 mg/m(2) days 1-7 orally and bevacizumab 10 mg/kg body weight i.v. day 1 every 2 weeks until disease progression or unacceptable toxicity. The primary end point was disease stabilisation rate [complete response (CR), partial response (PR) or stable disease (SD)] at week 12 (DSR12); secondary end points were best overall response, PFS, overall survival (OS) and adverse events.

RESULTS

Sixty-two patients (median age 59 years) enrolled at nine Swiss centres. DSR12 was 52% (PR: 10 patients and SD: 22 patients). Confirmed overall response rate was 16.1% (CR: 1 patient and PR: 9 patients). Median PFS and OS were 4.2 and 9.6 months. OS (12.0 versus 9.2 months; P = 0.014) was higher in BRAF V600E wild-type patients.

CONCLUSIONS

The primary end point was surpassed showing promising activity of this bevacizumab/temozolomide combination with a favourable toxicity profile. Response and OS were significantly higher in BRAF wild-type patients.

Phase I safety study of lenalidomide and dacarbazine in patients with metastatic melanoma previously untreated with systemic chemotherapy

This phase I trial assessed the maximal tolerated dose (MTD) of dacarbazine in combination with lenalidomide in metastatic melanoma. Cohorts of three to six patients with metastatic melanoma without brain metastases were enrolled at each of three dose levels of dacarbazine: 600 mg/m², 800 mg/m², and 1000 mg/m² administered intravenously every 3 weeks. Lenalidomide (25 mg/day) was administered orally for 14 days followed by a 7-day rest. Safety was assessed every 3 weeks, and tumor response was evaluated every 6 weeks. An additional 10 patients were enrolled in an expansion cohort at MTD level. Twenty-eight chemotherapy-naive patients were enrolled. The MTD was determined to be dose level 2 (800 mg/m²). Three patients experienced a grade 4 adverse reaction; two pulmonary emboli and one cerebral ischemia. Two patients had a deep venous thrombosis. Of 27 patients assessable for disease response, two experienced a complete response and four experienced a partial response. The median overall survival was 10.6 months (range 1.6-46.0+ months). One patient had a small brain lesion at the baseline; 10 additional patients developed brain metastasis at 0-10.8 months after completion of study therapy. The combination of dacarbazine and lenalidomide is safe and well tolerated in patients with metastatic melanoma. Clinical activity was seen at the MTD level. Additional measures to prevent brain metastasis are needed for patients who achieve a response.

Bevacizumab and everolimus in the treatment of patients with metastatic melanoma: a phase 2 trial of the Sarah Cannon Oncology Research Consortium

BACKGROUND

In this phase 2 study, the activity and tolerability of the combination of bevacizumab, an inhibitor of angiogenesis, and everolimus, an inhibitor of the mammalian target of rapamycin (mTOR), was evaluated in the treatment of patients with metastatic melanoma.

METHODS

Patients with metastatic melanoma who had received up to 2 previous systemic regimens (chemotherapy and/or immunotherapy) were eligible. Previous treatment with angiogenesis or mTOR inhibitors was not allowed. All patients received bevacizumab at a dose of 15 mg/kg intravenously every 21 days and everolimus at a dose of 10 mg orally daily. Patients were re-evaluated every 6 weeks; those with an objective response or stable disease (according to Response Evaluation Criteria in Solid Tumors [RECIST]) continued therapy until tumor progression or unacceptable toxicity occurred.

RESULTS

Fifty-seven patients with metastatic melanoma received a median of 4 treatment cycles (range, 1-14+ cycles). Seven patients (12%) achieved major responses, whereas 33 patients (58%) were found to have stable disease at the time of first evaluation. The median progression-free and overall survivals were 4 months and 8.6 months, respectively. Approximately 43% of patients were alive after 12 months of follow-up. The treatment regimen was well tolerated by the majority of patients.

CONCLUSIONS

The combination of bevacizumab and everolimus was found to have moderate activity and was well tolerated in the treatment of patients with metastatic melanoma. Further exploration of agents with these mechanisms of action is indicated, perhaps in combination with inhibitors of the mitogen-activated protein kinase (MAPK) pathway.

Erythropoietin is involved in angiogenesis in human primary melanoma

In this study, the extent of angiogenesis, evaluated as microvascular volume density, immunoreactivity of tumour cells to erythropoietin (Epo) and of endothelial cells to Epo receptor (EpoR) have been correlated in human primary melanoma specimens. Results showed that Epo/EpoR expression correlate with angiogenesis and tumour thickness. These findings suggest that Epo is secreted by tumour cells and it affects vascular endothelial cells via its receptor and promotes angiogenesis in a paracrine manner, playing an important role in melanoma angiogenesis.

Results of a multicenter, randomized, double-blind phase 2/3 study of lenalidomide in the treatment of pretreated relapsed or refractory metastatic malignant melanoma

BACKGROUND

The results of an international, multicenter, randomized, double-blind, controlled study assessing the efficacy and safety of lenalidomide treatment in patients with refractory stage IV metastatic malignant melanoma are reported.

METHODS

The study compared treatment with lenalidomide (25 mg/d on Days 1-21 of a 28-day cycle) to placebo in 306 patients with metastatic malignant melanoma. Treatment was continued until progression of disease or unacceptable toxicity.

RESULTS

There were no significant differences between lenalidomide and placebo in overall survival (median 5.9 months vs 7.4 months, respectively; P = .32), time to progression (median 3.0 months vs 2.1 months; P = .19), or Response Evaluation Criteria in Solid Tumors tumor response (5.3% vs 5.8%; P = .82). None of the patients given placebo discontinued treatment because of treatment-related adverse events, compared with 4.6% of those treated with lenalidomide. Treatment-related myelosuppression was observed in 2.0% of patients treated with placebo and 7.3% of patients treated with lenalidomide.

CONCLUSIONS

This study showed that treatment with lenalidomide (25 mg/d) has a manageable safety profile in patients with previously treated metastatic malignant melanoma but no benefit in tumor response, time to progression, or overall survival in these patients. Future trials for treatment of metastatic malignant melanoma with lenalidomide should focus on its use in combination therapies.

Angiogenesis and melanoma

Angiogenesis occurs in pathological conditions, such as tumors, where a specific critical point in tumor progression is the transition from the avascular to the vascular phase. Tumor angiogenesis depends mainly on the release by neoplastic cells of growth factors specific for endothelial cells, which are able to stimulate the growth of the host's blood vessels. This article summarizes the literature concerning the relationship between angiogenesis and human melanoma progression. The recent applications of antiangiogenic agents which interfere with melanoma progression are also described.

Temozolomide for the treatment of metastatic melanoma

Questions

What is the role of single-agent temozolomide in the treatment of patients with metastatic melanoma?

In comparison with single-agent temozolomide, does the addition of interferon-α to temozolomide improve disease-free survival, overall survival, or response rates?

In comparison with single-agent temozolomide, does the addition of thalidomide to temozolomide improve disease-free survival, overall survival, or response rates?

Perspectives

Because of its oral route of administration and its ability to cross the blood–brain barrier, temozolomide is a potentially attractive chemotherapy agent for adult patients with unresectable metastatic malignant melanoma. To provide treatment recommendations for this new agent, the Melanoma Disease Site Group (dsg) of Cancer Care Ontario’s Program in Evidence-Based Care (pebc) decided to review the available literature on single-agent temozolomide and on temozolomide in combination with interferon-α or thalidomide.

Outcomes

Outcomes of interest included response rates, disease-free survival, overall survival, quality of life, and adverse effects.

Methodology

Evidence was selected and reviewed by two members of the Melanoma dsg and by methodologists. The present practice guideline report was reviewed and approved by the Melanoma dsg, which comprises medical and radiation oncologists, surgeons, and dermatologists. External review was obtained through a mailed survey of Ontario practitioners, the results of which were reflected in revisions to the practice guideline. Final approval of the guideline report was obtained from the Report Approval Panel of the pbec.

Practice Guideline

These recommendations apply to adult patients with unresectable metastatic malignant melanoma.

It is reasonable to use temozolomide at a dose of 200 mg/m² orally for 5 days every 4 weeks as initial systemic treatment for patients with unresectable metastatic malignant melanoma.

The addition of moderate-dose interferon-α 2b has produced a significantly higher response rate than has single-agent temozolomide in a large randomized phase iii study. However, overall survival was not altered, and grades 3 and 4 hematologic toxicities were higher with the combined treatment. At the present time, the addition of interferon-α to temozolomide is not recommended.

One randomized phase ii study and six other phase ii studies showed encouraging response rates when thalidomide was combined with temozolomide. However, the doses and schedules of temozolomide in those studies differed from the conventionally prescribed doses and schedules. It is not clear whether the improved response rates were attributable to the small number of patients in the studies, the different temozolomide doses and schedules, or the addition of thalidomide. Further phase iii studies are required to confirm whether a benefit is associated with the combination of temozolomide and thalidomide. Therefore, at this time, it is not recommended that thalidomide be combined with temozolomide.

Qualifying Statements

Dacarbazine is the only chemotherapy drug currently approved for the treatment of metastatic malignant melanoma. In large randomized trials, response rates with dacarbazine ranged from 6% to 15%. Almost all responses were partial, with a median response duration of only 7–8 months. Given these disappointing overall results, the consensus among most physicians who are treating patients with metastatic malignant melanoma is that recommending more convenient treatment or experimental treatment to these patients is appropriate.

Because of oral dosing, temozolomide is a reasonable choice, particularly for patients who would have difficulty traveling to cancer centres for intravenous chemotherapy.

Temozolomide has demonstrated efficacy equal to that of dacarbazine in a randomized phase iii trial. However, unlike dacarbazine, temozolomide is a convenient oral treatment that penetrates the blood–brain barrier and that has shown activity against brain metastases. Although surgery is the preferred treatment modality for patients with solitary brain metastases from melanoma, temozolomide is the preferred chemotherapy for patients with brain metastases who require systemic treatment.

Phase 2 trial of combination thalidomide plus temozolomide in patients with metastatic malignant melanoma: Southwest Oncology Group S0508

BACKGROUND

In limited institution phase 2 studies, thalidomide and temozolomide has yielded response rates (RRs) up to 32% for advanced melanoma, leading to the use of this combination as "standard" by some. We conducted a multicenter phase 2 trial to better define the clinical efficacy of thalidomide and temozolomide and the immune modulatory effects of thalidomide, when combined with temozolomide, in patients with metastatic melanoma.

METHODS

Patients must have had stage IV cutaneous melanoma, no active brain metastases, Zubrod PS 0-1, up to 1 prior systemic therapy excluding thalidomide, temozolomide, or dacarbazine, adequate organ function, and given informed consent. The primary endpoint was 6-month progression-free survival (PFS). Secondary endpoints included overall survival (OS), RR, toxicities, and assessment of relationships between biomarkers and clinical outcomes. Patients received thalidomide (200 mg/d escalated to 400 mg/d for patients <70, or 100 mg/d escalated to 250 mg/d for patients > or =70) plus temozolomide (75 mg/m(2)/d x 6 weeks, and then 2 weeks rest).

RESULTS

Sixty-four patients were enrolled; 2 refused treatment. The 6-month PFS was 15% (95% confidence interval [CI], 6%-23%), the 1-year OS was 35% (95% CI, 24%-47%), and the RR was 13% (95% CI, 5%-25%), all partial. One treatment-related death occurred from myocardial infarction; 3 other grade 4 events occurred, including pulmonary embolism, neutropenia, and central nervous system (CNS) ischemia. There was no significant correlation between biomarkers and PFS or OS.

CONCLUSIONS

This combination of thalidomide and temozolomide does not appear to have a clinical benefit that exceeds dacarbazine alone. We would not recommend it further for phase 3 trials or for standard community use.

Compounds in clinical Phase III and beyond

Targeted therapies against cancer have become more and more important. In particular, the inhibition of tumor angiogenesis and vascular targeting have been the focus of new treatment strategies. Numerous new substances were developed as angiogenesis inhibitors and evaluated in clinical trials for safety, tolerance, and efficacy. With positive study results, some of these molecules have already been approved for clinical use. For example, this is true for the vascular endothelial growth factor neutralizing antibody bevacizumab (BEV) in metastatic colorectal cancer, nonsmall cell lung cancer, renal cancer, and breast cancer. The tyrosine kinase (TK) inhibitors sorafenib and sunitinib have been approved for metastatic renal cancer as well as for hepatocellular carcinoma, and sunitinib has also been approved for gastrointestinal stroma tumors. In this chapter we try to give an overview of the substances currently investigated in Phase III studies and beyond with regard to antiangiogenesis in cancer therapy.

Phase II Trial of Temozolomide and Sorafenib in Advanced Melanoma Patients with or without Brain Metastases

PURPOSE: The combination of the oral alkylating agent temozolomide and the oral multikinase inhibitor sorafenib was evaluated in advanced melanoma patients. EXPERIMENTAL DESIGN: Patients with metastatic melanoma (n = 167) were treated on four arms. All patients received sorafenib at 400 mg p.o. twice daily without interruption. Patients without brain metastases or prior temozolomide were randomized between arm A: extended dosing of temozolomide (75 mg/m(2) temozolomide daily for 6 of every 8 weeks) and arm B: standard dosing (150 mg/m(2) temozolomide daily for 5 of every 28 days). Patients previously treated with temozolomide were enrolled on arm C: extended dosing of temozolomide. Patients with brain metastases and no prior temozolomide were assigned to arm D: standard dosing. The primary end point was 6-month progression-free survival (PFS) rate. Secondary end points included response rate, toxicity rates, and the rates of BRAF or NRAS mutations. RESULTS: The 6-month PFS rate for arms A, B, C, and D were 50%, 40%, 11%, and 23%. The median PFS for patients on arm A, B, C, and D was 5.9, 4.2, 2.2, and 3.5 months, respectively. No significant differences were observed between arms A and B in 6-month PFS rate, median PFS, or response rates. Treatment was well tolerated in all arms. No significant differences in toxicity were observed between arms A and B except for more grade 3 to 4 lymphopenia in arm A. CONCLUSION: Temozolomide plus sorafenib was well tolerated and showed activity in melanoma patients without prior history of temozolomide. The activity of this combination regimen warrants further investigation. (Clin Cancer Res 2009;15(24):7711-8).

The history and future of chemotherapy for melanoma

Melanoma is considered a chemotherapy-resistant cancer, but in reality there are several chemotherapy drugs with significant single-agent activity. Response rates to combination regimens are reproducibly higher than with standard dacarbazine, but of the randomized trials comparing combination regimens with dacarbazine, none were of sufficient size to detect a realistic effect on survival. Similarly, adjuvant chemotherapy has not had a realistic test in melanoma. Response to chemotherapy is associated reproducibly with better survival rates suggesting that regimens with higher response rates are needed. Recent observations suggest that combining antiangiogenic agents with either dacarbazine or temozolomide can double response rates. These combinations are worthy of further investigation and might serve as a foundation on which to build a combination regimen that improves overall survival in metastatic melanoma patients.

Current systemic therapy for metastatic melanoma

Metastatic melanoma remains a lethal disease with a long-term remission rate of less than 10%. Despite many years of research, there has not been a new drug approved in this disease in over two decades. Single-agent chemotherapy is palliative in some patients and there is no advantage of combination chemotherapy or chemo-immunotherapy in randomized trials. High-dose bolus IL-2 produces some long-term remissions and is available for highly selected individuals at selected centers in the USA but is impractical for most patients. Research is ongoing in exploring novel immunotherapeutic and targeted approaches. The status of recently completed and ongoing trials is discussed in this review.

Molecular-targeted therapy in malignant melanoma

Malignant melanoma is a deadly disease in which standard treatment options have remained remarkably static over the past 30 years. Recent discoveries have expanded the understanding of the molecular processes critical to melanomagenesis. During this same time period, therapeutic agents have been developed that target these processes, leading to an explosion of preclinical research. Several agents that have shown promise in the preclinical setting have now entered clinical trials. To date, the success of these molecularly targeted approaches as single agents has been limited. Although more encouraging results have been seen when these agents have been used in combination with cytotoxic therapy, the specific contribution of the targeted agents to the observed anti-tumor effects remains to be established in randomized controlled Phase III trials. This article presents a review of the limitations of current therapy, a description of key pathogenic mechanisms for which inhibitors exist and a summary of therapeutic trials of molecularly targeted agents in this disease.

Management of malignant melanoma: best practices

BACKGROUND

Melanoma is a commonly occurring cancer in Canada, with an estimated age-standardized incidence of 10 to 13 per 100,000. An estimated 4,300 new cases were diagnosed, and there were 800 reported deaths in 2005.

OBJECTIVE AND CONCLUSION

The Canadian Expert Panel on Malignant Melanoma has developed best practices to improve the management of malignant melanoma. Sections include recommendations on primary diagnosis, dermatopathologic assessment, and reporting; use of preoperative lymphoscintigraphy and an intraoperative gamma probe to map and biopsy the sentinel lymph node; indications for surgical resection, sentinel node biopsy, and surgery for advance disease; use of interferon-alpha adjuvant therapy and treatment options for stage IV disease; and management of central nervous system metastases.

Selective Lymphopenia and Opportunistic Infections in Neuroendocrine Tumor Patients Receiving Temozolomide

Temozolomide is utilized as a treatment for a variety of solid tumors and has been associated with the development of selective lymphopenia. We evaluated the incidence of lymphopenia and opportunistic infections during treatment and up to 12 months following treatment discontinuation in a cohort of 39 patients receiving temozolomide for advanced neuroendocrine tumors. The incidence of Grade 3-4 lymphopenia was 46 percent after 4 months of therapy and remained at 30 percent or greater for 12 months following treatment discontinuation. The overall incidence of opportunistic infections was 10 percent, while among patients receiving therapy for > or =7 months, the incidence was 20 percent. Prophylaxis for Pneumocystis jiroveci pneumonia and varicella-zoster, as well as cytomegalovirus monitoring, should be considered in patients receiving temozolomide-based treatment.

Antifolate activity of pyrimethamine enhances temozolomide-induced cytotoxicity in melanoma cells

Most metastatic melanoma patients fail to respond to available therapy, underscoring the need to develop more effective treatments. We screened 2,000 compounds from the Spectrum Library in human melanoma cell lines to identify compounds that enhanced the cytotoxic effect of temozolomide, a drug used to treat metastatic melanoma. Screening was done with the temozolomide-resistant melanoma cell line SK-MEL-19, and six compounds were identified that had little or no inherent cytotoxicity but significantly enhanced growth-inhibition by temozolomide. These compounds were tested in five additional melanoma cell lines. Cell proliferation and death assays were used to compare the efficacy of single agent temozolomide versus combination treatments. Effects of combination treatment on levels of DNA double-strand breaks, the DNA repair protein O(6)-methylguanine-DNA-methyltransferase, apoptosis [measured by cleaved caspase-3 and poly(ADP-ribose) polymerase], and cell cycle were examined. Pyrimethamine, an antiparasitic, sensitized melanoma cells to temozolomide. Temozolomide combined with Pyrimethamine synergistically inhibited cell proliferation in melanoma cells with combination index values of 0.7 or less. In addition, combination treatment induced cell cycle arrest and increased both DNA damage and apoptosis. The increase in cell death due to combination treatment was rescued by leucovorin. Other folate antagonists were also effective enhancers of temozolomide-induced cytotoxicity, and the effects of antifolates were also evident in gliomas. Our screening approach led to the identification of Pyrimethamine, an orally available drug that efficiently crosses the blood-brain barrier, as a potent enhancer of the efficacy of temozolomide as an antineoplastic agent via inhibition of folate metabolism.

Temozolomide, thalidomide, and whole brain radiation therapy for patients with brain metastasis from metastatic melanoma: a phase II Cytokine Working Group study

BACKGROUND

The combination of temozolomide (TMZ) and thalidomide was reported to produce a high response rate, including shrinkage of brain metastases, in patients with metastatic melanoma. The authors tested the efficacy of a regimen including TMZ, thalidomide, and whole brain radiation therapy (WBRT) in patients with brain (CNS) metastases from melanoma.

METHODS

Patients with melanoma, CNS metastases documented by magnetic resonance imaging, and no prior systemic chemotherapy received WBRT, 30 Gray in 10 fractions, Days 1 to 5 and 8 to 12; TMZ, 75 mg/m(2)/day, Weeks 1 to 6; and thalidomide, 100 mg/day, Weeks 1 to 4, then escalated by 100 mg/day at Weeks 5, 7, and 9 as tolerated to a maximum of 400 mg/day. CNS and systemic tumor response was assessed at Week 10. Patients without CNS or clinically significant systemic disease progression received additional cycles of TMZ at 10-week intervals.

RESULTS

Thirty-nine patients received treatment, and 3 exhibited CNS response (1 complete response, 2 partial responses) (response rate, 7.6%; 95% confidence interval, 0.7%-16.1%), all unconfirmed by repeat imaging. Seven patients had stable CNS disease at 10 weeks. No patient exhibited a systemic response. Only 4 patients received 2 cycles of therapy, and just 1 received 3. Median time to progression was 7 weeks, and median overall survival was 4 months. Grade 3-4 side effects included deep venous thrombosis (3), pulmonary embolism (1), and CNS events (12). Eighteen (45%) patients required admission for side effects (7) and/or symptomatic disease progression (11).

CONCLUSIONS

The efficacy of TMZ, thalidomide, and WBRT in the treatment of CNS metastatic melanoma is low. Other treatment approaches should be considered for this patient population.

Phase II Study of Temozolomide and Thalidomide in Patients with Unresectable or Metastatic Leiomyosarcoma

We assessed the efficacy of combined temozolomide and thalidomide in patients with unresectable or metastatic leiomyosarcoma in a phase II single-institution trial. Twenty-four patients were enrolled. Temozolomide (150 mg/m(2)/day for 7 days every other week) was administered with concomitant thalidomide (200 mg/day), and continued until unacceptable toxicity or disease progression. There were no complete responses and two (10%) partial responses. Five patients (24%) had stable disease for at least six months. Fourteen patients (67%) progressed after a median of two-month treatment. The median overall survival (twenty-two assessable patients) was 9.5 months [95% CI 7-28 months]. There were no treatment-related deaths or CTC grade 4 toxicities. Thirteen patients were dose-reduced or discontinued thalidomide due to toxicity. In conclusion, this combination of temozolomide and thalidomide provided disease stabilization in a subset of patients with advanced leiomyosarcoma. We hypothesize that temozolomide is the active agent in this regimen, and should be further studied.

Fibrin sealant does not decrease seroma output or time to drain removal following inguino-femoral lymph node dissection in melanoma patients: a randomized controlled trial (NCT00506311)

Background

This study assessed the impact of closed suction drains and evaluated whether the intraoperative use of a fibrin sealant decreased time to drain removal and wound complications in melanoma patients undergoing inguino-femoral lymph node dissection.

Methods

A pilot study (n = 18) assessed the impact of a closed suction drain following inguino-femoral lymph node dissection. A single-institution, prospective trial was then performed in which patients were randomized to a group that received intraoperative application of a fibrin sealant following inguino-femoral lymph node dissection or to a control group that did not receive sealant.

Results

The majority of the patients enrolled felt the drains caused moderate or severe discomfort and difficulties with activities of daily living. Thirty patients were then randomized; the median time to drain removal in the control group (n = 14) was 30 days (range, 13–74) compared to 29 days (range, 11–45) in the fibrin sealant group (n = 16; P = 0.6). Major and minor complications were similar in the two groups.

Conclusion

Postoperative closed suction drains were associated with major patient inconvenience. Applying a fibrin sealant at the time of inguino-femoral lymph node dissection in melanoma patients did not reduce the time to drain removal or postoperative morbidity. Alternative strategies are needed.

A rational surgical approach to the treatment of distant melanoma metastases

The optimal treatment of melanoma involves multidisciplinary care. To many, this means surgical resection of early, localized disease and treatment of metastatic disease with chemotherapy, immunotherapy, or radiation. Because it is effective, results in little morbidity and may be repeated, surgery should have a central role in the treatment of selected patients with American Joint Committee on Cancer (AJCC) stage IV melanoma.

Phase II study of extended-dose temozolomide in patients with melanoma

PURPOSE

We conducted a phase II trial of extended-dose temozolomide (TMZ) in patients with melanoma to test the hypothesis that the approximately 30% response rate observed in patients treated with extended-dose TMZ with antiangiogenic agents was caused by TMZ alone. We hypothesized that expression of methylguanine methyltransferase (MGMT) in the tumor would correlate with drug resistance to TMZ.

PATIENTS AND METHODS

Patients with stage IV or unresectable stage III melanoma were treated with TMZ 75 mg/m(2)/d for 6 weeks followed by a 2-week rest period. Cycles were repeated until progression. Patients were stratified by M1c disease or not. The primary end point was objective response proportion. MGMT expression was assessed by methylation-specific pyrosequencing of the promoter and by immunohistochemistry.

RESULTS

Forty-nine patients (25 with M1c disease) were assessable. Three patients (12.5%) in each cohort experienced partial responses; there were no complete responses. Ten patients (21%) had stable disease lasting more than 24 weeks. Median time to progression was 3.3 months. Median survival was 10.1 months; survival was similar in the two cohorts. The estimated 18-month survival was 27%. There was no correlation between response and either immunohistochemistry staining for MGMT or for MGMT promoter methylation. Seventy-five percent of patients developed CD4(+) lymphopenia after three cycles.

CONCLUSION

Extended-dose TMZ therapy did not result in a 30% responses rate, which has been observed using extended-dose TMZ with antiangiogenic agents. Response did not correlate with MGMT expression or promoter methylation as a continuous variable, suggesting that other resistance mechanisms are important.

[Experimental treatment of malignant melanoma and its rationale]

To treat malignant melanoma successfully currently means to recognize the tumor at an early stage and to remove it immediately. Aside from individual cases, available treatment modalities are not able to increase survival, especially in the palliative situation. Thus innovative experimental approaches are urgently needed to strongly improve the palliative and adjuvant treatment of melanoma. Anti-tumor effects are expected from targeted therapies, which are directed against defined molecules decisive for tumor pathogenesis. Crucial points of attack are signaling pathways, angiogenesis and apoptosis resistance. New diagnostic and therapeutic developments have enhanced the efficacy of chemotherapies. Increasing insights into tumor immunology provide new treatment approaches of vaccination, cell transfer and especially of blocking immune tolerance mechanisms. It will be challenging for the future to identify and characterize more precisely those patients who might most benefit from a certain treatment approach.

Treatment of melanoma and nonmelanoma skin cancer

The incidence of skin cancer is increasing in Caucasian populations worldwide. Treatment approaches for Nonmelanoma skin cancer (NMSC) are predominantly curative and surgery can be regarded as standard of care. Nevertheless, novel and less invasive topical therapy modalities like photodynamic therapy or local immune modifiers are in progress. In contrast to NMSC, the mortality of melanoma has not changed considerably over the last years and decades. Melanoma survival mainly depends on primary tumor thickness underlining the importance of primary and secondary prevention by avoidance or early detection of the disease. The chance to cure melanoma patients is steadily decreasing with tumor stage. As the prognosis in distant metastatic disease is still poor, except for single situations therapy approaches are palliative and accompanied by an optimal supportive care of the patients concerned. Albeit removal of localized metastases is currently the most effective approach in metastatic melanoma, chemo- and chemoimmunotherapy has to be regarded as standard treatment in most of the cases. Novel and promising therapeutic options accrue from growing insights in tumor biology and immunology. Not only in melanoma, development and application of targeted therapies currently attract the most attention in the treatment of advanced tumors. First clinical experiences with those antiproliferative, antiangiogenic and proapoptotic agents reveal only moderate antitumoral activity in melanoma, so that future efforts aim at defining more effective combination strategies using chemo-, targeted and vaccination therapy approaches.

Evaluation of interferon alpha-2B and thalidomide in patients with disseminated malignant melanoma, phase 2, SWOG 0026

BACKGROUND

Southwest Oncology Group protocol 0026 evaluated interferon alpha-2b plus thalidomide in patients with disseminated melanoma. Endpoints were 6-month progression-free survival rate, response rate, and toxicity.

METHODS

Twenty-six patients with Stage IV melanoma, measurable or nonmeasurable disease, performance status of 0-2, and adequate renal and hepatic functions were registered. One prior systemic therapy for Stage IV disease was required. Interferon was administered subcutaneously (1 million U) twice daily; thalidomide was orally administered (200-400 mg) each evening in a dose-escalating manner. Response evaluations using Response Evaluation Criteria in Solid Tumors were performed every 8 weeks.

RESULTS

After 2 sudden deaths and 1 grade 4 treatment-related pulmonary embolism, this study was temporarily closed. One patient with deep-vein thrombosis and 2 with grade 3 cardiac arrhythmias were reported. The relationship of these events to the treatment was worrisome but not definitive. Grade 3 treatment-related adverse events occurred in 14 of 26 patients. Because of concern for patient safety the study was permanently closed. No treatment responses were seen in the 22 evaluable patients. Estimated 6-month progression-free survival rate was 15% (95% confidence interval [CI], 2%-29%), estimated 6-month overall survival was 58% (95% CI, 39%-77%), and estimated response probability was 0 of 22 (95% CI, 0%-15%).

CONCLUSIONS

This regimen demonstrated a lack of response and was associated with multiple severe toxicities. Further investigation of interferon alpha-2b and thalidomide in this dose and schedule is not warranted.

Temozolomide for the treatment of metastatic melanoma: a systematic review

BACKGROUND

This systematic review examines the role of temozolomide in patients with metastatic melanoma. Outcomes of interest include response rate, progression-free survival, overall survival, quality of life, and adverse effects.

METHODS

The MEDLINE, EMBASE, and Cochrane Library databases were searched from 1980 through to 2005 using variations on the search terms: melanoma, clinical trial, random, temozolomide, temodal, and temodar. The American Society of Clinical Oncology Annual Meeting proceedings were searched from 1996 to 2005. Relevant articles and abstracts were selected and reviewed by two reviewers, and the reference lists from these sources were searched for additional trials.

RESULTS

Two randomized phase III trials and three randomized phase II trials were located. In addition, 21 phase I or II trials investigating single-agent temozolomide, temozolomide plus interferon-alpha, and temozolomide plus thalidomide were reviewed. A direct comparison of temozolomide and dacarbazine demonstrated equal efficacy for response rates and overall survival; however, no significant difference was reported. A second phase III study comparing single-agent temozolomide with temozolomide combined with interferon-alpha indicated a significantly higher response rate for the combination treatment arm, but no difference in overall survival was noted. Further phase III studies are required to confirm whether there is a benefit associated with the combination of temozolomide and interferon-alpha or thalidomide.

CONCLUSION

Our review of the available literature suggests that temozolomide demonstrates comparable activity to the current standard treatment, dacarbazine, with the additional benefit of being a convenient oral treatment that penetrates the blood-brain barrier.

Temozolomide in combination with fotemustine in patients with metastatic melanoma

PURPOSE

Temozolomide and fotemustine are both active drugs for treating metastatic melanoma. The present study was designed to assess the efficacy and safety of combination therapy with temozolomide + fotemustine in patients with metastatic melanoma.

METHODS

Forty patients (median age 50.5 and 22 males) with pathologically confirmed, unresectable, AJCO stage IV melanoma were enrolled into the study. The primary endpoints were tumor response and safety. Patients received oral temozolomide 125 mg/m(2) on days 1-7 and intravenous fotemustine 80 mg/m(2) on day 3 every 3 weeks.

RESULTS

Fourteen (35%) patients achieved an objective response, including 3 (7.5%) complete and 11 (27.5%) partial responses. Median overall survival time was 6.7 months and 6-month survival rate was 57.4%. Myelosupression, particularly thrombocytopenia, was the primary toxicity.

CONCLUSION

The regimen, temozolomide combined with fotemustine, is an active and moderately safe first-line chemotherapy regimen with acceptable and easily manageable toxicities in patients with metastatic melanoma.

Early experience with novel immunomodulators for cancer treatment

Immunotherapy involves the treatment of cancer by modification of the host-tumour relationship. It is now known that this relationship is quite complex and only some of the interactions have been elucidated. Early attempts at immunotherapy, such as Coley's toxins, were undertaken without an understanding of the processes mediating the effects. With a better understanding of the immunology of this anticancer response, recent trials have focussed on certain aspects of the process to stimulate an antitumour response. In this review, the authors discuss a number of novel biological response modifiers that work as general stimulants of the immune system, through varied mechanisms including induction of stimulatory cytokines (such as IFN-alpha, TNF-alpha and IL-12) and activation of T cells and the antigen-presenting dendritic cells. These compounds include Toll-like receptor agonists, several of which are in clinical trials at present. In addition to immunomodulatory activity, some compounds such as 5,6-dimethylxanthenone-4-acetic acid (DMXAA) and thalidomide and its analogues also target existing or developing tumour vasculature. Some of these compounds have single-agent activity in clinical trials, while others such as DMXAA have shown promise in combination with chemotherapy without increasing toxicity. Lactoferrin is another compound that has shown clinical activity with low toxicity. At present, accepted indications for immunotherapy are limited to a few cancers such as renal cell carcinoma and melanoma. This paper looks at some of the reasons for the limited impact of immunotherapy so far and suggest possible avenues for further research with a greater likelihood of success.

A pilot study of low-dose thalidomide and interferon alpha-2b in patients with metastatic melanoma who failed prior treatment

Melanoma is a hypervascular tumor and angiogenesis plays a critical role in the development/progression of metastases. As various pathways are involved in tumor angiogenesis, a combination of agents with different antiangiogenesis activities is a reasonable approach. To determine the efficacy and toxicity of combination treatment with low-dose thalidomide and low-dose interferon (IFN) in patients with stage IV melanoma who failed prior treatment(s), fifteen patients with metastatic melanoma (nine cutaneous, six uveal) received oral thalidomide (200 mg daily) with subcutaneous interferon (IFN)-alpha2b (3 MIU, 3x/week). Stabilization or regression of metastases (as evidenced by computed tomographic measurement) was the primary endpoint of the study. Patients were evaluated monthly for toxicity and every 2 months for clinical response. At a median follow-up of 22.8 months (range, 12-32 months), one patient with metastatic cutaneous melanoma achieved partial response, three patients achieved stable disease (one uveal, two cutaneous), nine patients progressed, and two were not evaluable. The time to progression was 6 months for the patient with partial response, and 2, 5.5+ and 11 months for three patients with stable disease. The estimated median overall survival was 4.7 months (confidence interval, 2.2-9.9 months; range, 0.9-31.5 months), and median progression-free survival was 1.8 months (confidence interval, 1.5-3.0 months; range, 0.5-14 months). Grade 3 toxicities related to treatment included neutropenia (n=5), elevation of transaminases (n=2), and neuropathy (n=1). No treatment-related deaths were experienced. Thalidomide+IFN is a safe and tolerable palliative treatment for previously treated stage IV melanoma.

A phase II trial of thalidomide and cyclophosphamide in patients with recurrent or refractory pediatric malignancies

BACKGROUND

Previous clinical and pre-clinical research has demonstrated synergy between anti-angiogenic agents and cytotoxic chemotherapy. This trial was undertaken to investigate whether the combination of cyclophosphamide and thalidomide would be active against pediatric tumors.

PROCEDURE

Patients with pediatric malignancies who had no remaining conventional therapeutic options were recruited from January 1999 to May 2001. They received thalidomide (6-12 mg/kg po every day; maximum daily dose 800 mg) and cyclophosphamide (1,200 mg/m2 IV every 28 days).

RESULTS

Twenty-seven patients were enrolled on the study. Seventeen were male and 10 were female. Median age at the time of registration was 15 years (range 1-54 years). The median number of prior treatment regimens was four. Twenty-one patients were evaluable for response; 1 had a partial response (Hodgkin disease), 1 demonstrated stable disease (neuroendocrine tumor), and 19 had progressive disease. The most common toxicities were hematological (leukocytopenia and neutropenia) and gastrointestinal. One patient experienced a grade 3 rash. Fatigue and daytime somnolence were variable. No peripheral neuropathy was observed.

CONCLUSION

The combination of thalidomide and cyclophosphamide as described herein has a modest and tolerable toxicity profile but little evidence of efficacy.

A phase II study of ABT-510 (thrombospondin-1 analog) for the treatment of metastatic melanoma

OBJECTIVES

Thrombospondins are natural inhibitors of angiogenesis, tumor metastases, and tumor growth (melanoma). ABT-510 is a synthetic analog of thrombospondin-1, well tolerated in phase I studies. We conducted a phase II trial evaluating the clinical efficacy of ABT-510 and its effects on biomarkers of angiogenesis and immunity in patients with metastatic melanoma (MM).

PATIENTS AND METHODS

A 2-stage phase II clinical trial was conducted to assess the clinical efficacy, safety, and pharmacodynamic effects (angiogenesis and immunity) of ABT-510 in patients with stage IV melanoma. The primary endpoint was 18-week treatment failure rate. Patients self-administered 100 mg of ABT-510 subcutaneously twice daily. Blood samples were collected at baseline and every 3 weeks while on therapy. Eligible patients demonstrated measurable disease, good performance status and no evidence of intracranial metastases. Correlative laboratory studies evaluated biomarkers of angiogenesis and immunity.

RESULTS

Twenty-one patients were enrolled. Most patients were stage M1c (71%) and all had prior therapy for MM. Only 3 of the first 20 patients enrolled were progression free and on treatment at 18 weeks resulting in early termination of the study. Decreases in peripheral blood VEGF-A levels and VEGF-C levels, and CD146 and CD34/133 counts relative to pretreatment were detected. Limited changes in antitumor T cell immunity were observed.

CONCLUSIONS

ABT-510 therapy administered at 100 mg twice/day in patients with MM did not demonstrate definite clinical efficacy. Further dose escalation or combination with cytotoxic therapy may be more effective therapeutically.

Phase II study of thalidomide in patients with metastatic carcinoid and islet cell tumors

PURPOSE

Carcinoid and islet cell tumors are known to be highly vascular. There is no effective systemic therapy currently available for metastatic disease. We conducted a phase II trial to evaluate the efficacy of the anti-antiangiogenic agent thalidomide in metastatic neuroendocrine tumors.

PATIENTS AND METHODS

Eighteen patients with measurable, histologically proven metastatic carcinoid neuroendocrine carcinomas (well-differentiated, n = 13; moderately-differentiated, n = 5) were enrolled on this study. The majority of the patients had gastrointestinal primaries (small bowel, 8; pancreas, 5; colon, 1). All but one patient had hepatic metastases, and 12 patients (67%) had carcinoid syndrome. All patients had Eastern Cooperative Oncology Group performance status of zero or one. Eight patients (44%) had received previous hepatic artery chemoembolization and 11 (61%) had undergone surgical resection. Patients were started on oral thalidomide at a daily dose of 200 mg that was escalated to the target dose of 400 mg daily after 2 weeks. Tumor response was assessed at 12-week intervals using RECIST criteria. Planned treatment duration was 24 weeks unless unacceptable toxicity or disease progression was observed.

RESULTS

No patient achieved a partial remission or a complete remission. Best response was stable disease (SD) in 11 of 16 response-evaluable patients (69%). Serum pancreastatin results did not correlate with clinical response. Grade 3 toxicities included dizziness with orthostatic hypotension (n = 5), sensory neuropathy (n = 2), fatigue (n = 2), hemorrhagic cystitis (n = 1), and deep venous thrombosis (n = 1). Frequent Grade 1-2 toxicities were: fatigue (n = 13), constipation (n = 13), dry mouth (n = 12), somnolence (n = 12), dizziness/syncope (n = 10), weight gain (n = 5), and peripheral neuropathy (n = 5).

CONCLUSIONS

Thalidomide was fairly well tolerated in patients with metastatic carcinoid/islet cell tumors, but failed to reveal any objective responses. The single stage design of the trial makes it difficult to determine whether observed SD in a subset of patients was attributable to the indolent nature of these tumors, or to beneficial effect of thalidomide.

New approaches in metastatic melanoma: biological and molecular targeted therapies

Classical metastatic melanoma therapy is disappointing but important progress has been made in the understanding of melanoma biology. Genetic lesions and several intracellular signaling pathways that could serve as targets for novel therapy have been identified and a number of new agents are under evaluation. Promising tumor cell targets were identified in the cell membrane, cytoplasm and nucleus. New therapeutic approaches, besides monoclonal antibodies and vaccination, include an increasing number of small molecules that have been shown to interfere restrictively with intracellular signaling pathways in melanoma and decrease proliferation, survival, migration or invasion. Other agents can interfere with stromal components of melanoma, such as angiogenesis and components of the immune system.

Current topics in melanoma

PURPOSE OF REVIEW

New approaches to melanoma are emerging. This review summarizes developments over the past 12 months.

RECENT FINDINGS

Surgical, chemotherapeutic, immunologic and targeted therapies for melanoma are evolving. Sentinel lymph node sampling is now accepted as the standard of care for patients with intermediate thickness primary melanomas. Temozolomide continues to be widely used as part of combination therapy, and recent evidence suggests that a combination of temozolomide and interferon-alpha may be superior to temozolomide alone. Meanwhile, temozolomide and thalidomide carries unacceptable thrombosis risk. In the area of immunotherapy, anti-CTLA-4 continues to show promise, but special attention must be paid to gastrointestinal toxicity. Interferon-alpha, in addition, has shown efficacy in the neoadjuvant setting with inflammatory infiltrates demonstrated in tumors. A better understanding of the complex genetic regulation of melanoma cell growth is emerging and this is expected to lead to the development of novel targeted therapies.

SUMMARY

Research is producing a more complete understanding of melanoma genetics and immune regulation. These are beginning to produce therapeutics that are impacting clinical practice.

Vascular endothelial growth factor and immunosuppression in cancer: current knowledge and potential for new therapy

Two decades of research into the role of immunosuppression and angiogenesis in tumor biology have revealed multiple links between the two. Vascular endothelial growth factor, originally thought to be solely involved in vascular growth and permeability, has emerged as a significant agent of immune tolerance in the tumor microenvironment. This review examines two major elements of this field: the research behind the role of vascular endothelial growth factor in immunosuppression, especially as pertains to dendritic cell function; and the subsequent research into the potential for using antiangiogenic therapy to both starve tumors by hypoxia and enhance the response of tumors to immunotherapy. Several strategies tested so far have yielded incomplete, yet promising, results.